Substrate-Integrated Gasket Manufacturing via Multi-Stage Injection Molding
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Solution Overview
Problem
The existing methods for manufacturing substrate-integrated gaskets, particularly for fuel batteries, face challenges such as increased man-hours for burr removal and cleaning, material waste, and inefficient mold design due to rubber burr generation and handling issues during molding, which hinder downsizing and cost reduction.
Innovation Solution
The method involves using a fiber substrate made of pulp fibers with cellulose as the main component, integrated with a rubber-like elastic body through injection molding, where the rubber material is filled in multiple stages of metal mold cavities without through holes, and immobilizes fiber entanglement post-cross-linking, reducing burr generation and enhancing handling properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a gasket is manufactured using a rubber simple substance with metal mold compression molding, then the gasket can be produced, but rubber burr is generated due to gap in the metal mold, increasing man hour for burr removal and mold cleaning
Solution Approach 1:
The invention divides the molding process into multiple stages with different mold configurations. The first stage uses a mold with a release film to prevent burr generation, while the second stage removes the film and performs final molding. This segmentation of the molding process allows each stage to optimize for its specific function, eliminating the burr problem without compromising the final product quality.
Solution Approach 2:
The release film is applied in advance before the molding process begins. This preliminary action prevents rubber material from leaking into the gap between mold parts during molding, thereby preventing burr generation before it can occur. The film serves as a preventive measure that eliminates the need for subsequent burr removal operations.
2Productivity
If multiple product cavity spaces are arranged on the same plane of a metal mold for simultaneous molding, then production efficiency is improved, but the metal mold becomes enlarged in size
Solution Approach 1:
The invention transitions from arranging multiple cavity spaces on the same plane to stacking them in multiple layers along the mold opening direction. This dimensional change from 2D plane arrangement to 3D stacked arrangement allows multiple products to be molded simultaneously while maintaining a compact mold footprint, thus improving productivity without enlarging the mold's planar dimensions.
Solution Approach 2:
The mold structure is designed with nested or stacked cavity spaces where one cavity is positioned above another along the mold opening direction. This nesting arrangement allows multiple product cavities to occupy the same projected area, enabling simultaneous molding of multiple gaskets while keeping the mold compact in planar dimensions.
3Loss of substance
If injection molding is used to reduce material disposal, then material efficiency is improved, but rubber burr still generates requiring manual intervention
Solution Approach 1:
The release film is applied in advance before injection molding to prevent rubber material from generating burrs during the injection process. This preliminary protective action ensures that even though injection molding is used for material efficiency, the harmful burr generation is prevented from occurring in the first place, eliminating the need for subsequent burr removal operations.
Solution Approach 2:
The release film acts as an intermediary layer between the rubber material and the mold gap. During injection molding, this intermediate film prevents the rubber material from leaking into the gap and forming burrs, while still allowing the injection molding process to proceed for material-efficient production. The film mediates between the conflicting requirements of material efficiency and burr prevention.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces man-hours for burr treatment and mold cleaning, minimizes material waste, and improves manufacturing efficiency by suppressing rubber burr formation and enabling more compact mold designs, thus facilitating automation and cost reduction.
Implementation Method 1
the rubber material is filled in plural stages of metal mold cavities by passing the rubber material through the fiber substrate in which a rubber material flow channel in the metal mold is closed at its injection pressure
Implementation Method 2
the rubber material immobilizes fiber entanglement of the fiber substrate by the rubber impregnation after cross-linking
Data Source
AI summary
The invention provides a method for manufacturing a substrate-integrated gasket, the method integrating a fiber substrate which is constructed by a pulp fiber having cellulose as a main component and a gasket body which is constructed by a rubber-like elastic body according to a rubber impregnation, wherein a plurality of substrate-integrated gaskets are obtained by executing an injection molding by plural stages of rubber metal molds. Further, the rubber material is filled in plural stages of metal mold cavities by passing the rubber material through the fiber substrate in which a rubber material flow channel in the metal mold is closed at its injection pressure. The invention can reduce a man hour for removing burr and cleaning a metal mold by suppressing generation of rubber burr at the molding time and can reduce an amount of disposal of a molding material, thereby achieving a good manufacturing efficiency.